Stripper-holddown assembly for punch presses



United States Patent lnventor 3,140,630 7/1964 Wolf 83/140 7 FOREIGNPATENTS 950,807 2/1964 Great Britain 83/552 Primary Examiner-William S.Lawson Attorney-Paul & Paul ABSTRACT: A combination stripper andholddown is provided, carried by a punch press machine, either of thesingle station or turret types, as opposed to being carried by apunching ,tool or a tool adaptor. Such a mounting for the stripper andholddown combination permits ease of access to the tool holder andadaptor, for removal or replacement thereof, as for example during achange in tool size. In the single station type of punch press, thestripper and holddown assembly is mounted on a spacer carried by the ramadaptor and a dishlike plate, the plate having a lower planar surfacewhich engages a workpiece for clamping the same, with the stripper capbeing threadably connected into the dishlike plate. The turret type ofpunch press utilizes a platelike stripper and holddown-assembly. carriedby and axially movable relative to the rotary turret plate. andvertically driven by a C-shaped yoke or spacer which is spring carriedby the ram adaptor.

Patented Nov. 17, 1970 3,540,339

Sheet 1 013 U1 @@gl@l@ Fig. 4 Fig.3

INVENTOR. John S. Killoiy WPM ATTORNEYS.

Patented Nov. 17, 1970 Sheet ATTORNEYS.

Patented Nov. 17, 1970 3,540,339

I w 7 I -d l a v WP 9| INVENTOR.

M John S. Killoly BY 8 WwMZw ATTORNEYS.

STRIPPER-HOLDDOWN ASSEMBLY FOR PUNCH PRESSES BACKGROUND OF THE INVENTIONPunch presses of the prior art types have used stripper and holddowncombinations, but such stripper and holddown combinations or units thusutilized are generally mounted on or carried by either of the punchingtools, or tool adaptor, for example as disclosed in my own prior U.S.Pat. No. 3,296,905, granted Jan. 10, 1967.

Devices of this type have proven to be particularly desirable forapplying combination stripper-holddown units to existing punch presses,in that the units, particularly those disclosed in said above-mentionedpatent are compact and readily assembled onto existing punch adaptorsand the like.

While stripping and holddown assemblies of the above-mentioned patentedtype have been successful for modifying existing punch press machines,certain disadvantages are present in such units, such as the problem ofhaving to remove the stripper-holddown unit assembly whenever it isdesirable to change a punch and punch adaptor. Thus, there is a need forproviding in the punch press art, a stripper-holddown unit, wherein thestripper is generally of the stripper-plate type, and comprises a partof the holddown unit, and wherein the stripper-holddown unit is carriedin such a way as to permit ready accessability and quick-releaseinterchangeability of tools and tool adaptors, without requiring removalof the complete stripper-holddown unit carrier assembly.

SUMMARY OF THE INVENTION The present invention seeks to provide asolution to the problems discussed above, and to obviate the problem oftool and tool adaptor interchangeability and replacement, withoutinterference from the stripper-holddown spacer, in providing a punchpress apparatus having a stripper-holddown unit that is capable of quickrelease and that is, built into the machine itself, and carried thereby,as opposed to being carried, by a tool or tool adaptor, in order toprovide ready access for removal and interchangeability of tools andtool adaptors, but yet providing an effective stripper-holddowncombination utilizing a stripper of the plate type, thestripper-holddown unit being resiliently carried by the ram or ramadaptor, and being free of any support whatever from either of the toolor tool adaptor and being actuated through a spacer that spans the tooland tool adaptor.

Accordingly, it is a primary object of this invention to provide a punchpress, either of the single station or turret types, wherein acombination stripper-holddown spacer unit is mounted as an integral partof the machine, with the spacer and unit being free of attachment to andlateral support from either of the tool or tool adaptor, forfacilitating tool removal and replacement.

It is a further object of this invention to provide a punch press of thetype set forth immediately above, wherein the combinationstripper-holddown unit utilizes planar surface means for clamping aworkpiece against a lower die, wherein a stripper cap is provided,either of the self-punching or rotatable toolfollowing type.

It is a further object-of this invention to provide a punch press of thetype set forth in the objects above, wherein the press is of the singlestation type, and wherein the stripperholddown unit is carried by aspring seated plate mounted for axial movement along the ram adaptor,with the unit being a readily removable bottom dishlike member.

It is yet another object of this invention to provide a punch press ofthe turret type, utilizing a combination stripper and holddown unit,wherein the unit is carried by and is axially movable relative to arotatable turret, the axial movement of the unit being provided by ayoke member which itself is spring carried by a ram adaptor for verticalmovement relative thereto.

LII

Other objects and advantages of the present invention will be readilyapparent to one skilled in the art, from the following brief figuredescriptions, detailed descriptions of the preferred embodiments, andthe appended claims.

IN THE DRAWINGS FIG. 1. is a fragmentary vertical sectional view, takenthrough a single station punch press of this invention, wherein themounting ofa stripper-holddown unit to the machine itself is clearlyillustrated;

FIG. 2 is a bottom view of the punch head of the punch press illustratedin FIG. 1, taken generally along the line II-II of FIG. 1, with portionsbroken away and in section for purposes of clarity;

FIG. 3 is a fragmentary vertical sectional view through the punchingtool, die, and stripper-holddown unit of this invention, wherein thereis illustrated a stripper cap of the selfpunching type, with the toolbeing illustrated in phantom in a retracted position, and in full linesin an operative position, wherein the initial downward punchingoperation of the tool punches out the stripper cap to have atool-conforming periphery;

FIG.-4 is a fragmentary vertical sectional view through the punchingtool, die, spacer and stripper-holddown unit of this invention,generally similar to that of FIG. 3, but wherein a workpiece is disposedbetween the stripper-holddown unit and die, and wherein a punching-outofa portion of the workpiece by the punching tool is illustrated.

FIG. Sis an enlarged vertical sectional view through an alternativeembodiment of the stripper cap adapted for use with the press of thisinvention, wherein the stripper cap is of the tool-following type;

FIG. 6 is a fragmentary vertical sectional view through a turret-typepunch press of this invention, wherein the stripper plate is illustratedin position above the die, carried by the turret plate, with means beingillustrated for actuating the stripper-holddown unit for verticalmovement;

FIG. 7 is a fragmentary horizontal sectional view, through the punchpress of FIG. 6, taken generally along the line VII-VII of FIG. 6,wherein the turret plate is illustrated in plan view, and theyoke-shaped holddown actuation means is illustrated in section; and

FIG. 8 is a fragmentary vertical sectional view through the punch pressof this invention, illustrating generally the components illustrated atthe lower end of FIG. 6, but wherein the stripper-holddown unit is inclamping engagement against the workpiece, with the punching tool beingillustrated in one stage ofits punching operation.

Referring now to the drawings in detail, reference is first made to FIG.1, wherein there is illustrated a punch press generally designated bythe numeral 10, the press comprising a machine 11, a punching tool 12,and a tool adaptor 13.

The machine 11 includes a vertical movable cylindrical ram 14, beinggenerally downwardly movable toward a die 15, the die 15 being generallyfixedly positioned with respect to the ram 14. The various machine framecomponents by which the ram 14 and die 15 are supported are notillustrated herein, for the sake of clarity.

A ram adaptor 16 is provided, being generally of inverted hat-shapedsection, having a lower ram seating portion 17, a generally tubular wallportion I8, and a radially outwardly extending flange portion 20. Theouter peripheral surface 21 of the tubular portion 18 of the ram adaptor16 is generally smoothly contoured, for a sliding lit with an inner bore22 ofa mounting plate 23, the mounting plate 23 being disposed about theadaptor 16 for vertical sliding movement relative thereto.

A plurality of screws 24 are provided, equidistantly circumferentiallyspaced about the flange 20 of the ram adaptor 16 and the mounting plate23, for equally balancing pressures exerted on the mounting plate 23from associated springs 25 disposed about and carried by the screws 24.The springs 25 are in engagement against an upper surface 26 of themounting plate 23, and in engagement with a lower surface 27 of the ramadaptor flange 20, for biasing the mounting plate 23 downwardly. Thescrews 24 have threaded lower end portions 28, engaged withincorrespondingly tapped holes 30 of the mounting plate 23, and heads 31received within counterbores 32 of the flange 20. The shank 33 of eachof the screws 24 is freely slidable within a bore 34 of the flange 20,the screws 24 thus being adapted to limit the vertical downward movementof the mounting plate 23, by engagement of the screw heads 31 againstthe ram adaptor flange 20, thereby providing double action for the ramhead and a resilient seating for the workpiece clamping means later tobe described.

The ram adaptor 16 is connected to the ram 14 by a cap headed screw 35threadably connected within a tapped hole 36 of the ram 14, and inengagement with the seating portion 17 of the ram adaptor 16.

The punching tool 12 is illustrated to be of rectangular configuration,but any suitable configuration may be used. The tool 12 is receivablyengaged within its adaptor 13, by conventional means, and the adaptor 13has an upper boss portion 37 receivably engaged within a bore 38 of theram adaptor seating portion 17. The tool adaptor 13 also includes aperipheralmost portion 40 which is received within a bore 41 of aconnection plate 42, the connection plate being secured to the seatingportion 17 of the ram adaptor 16 by suitable screw fasteners 43 or thelike. An annular groove 44 is provided about the periphery of theportion 40 of the tool adaptor 13, for engagement therein of one end ofa horizontally disposed screw 45, which is threadably engaged within theconnection member 42, and is radially outwardly movable with respect tothe tool adaptor 13, to a position in which the innermost end of themember 45 clears the annular groove 44 of the adaptor 13, for removal ofthe adaptor 13, and attached tool 12 from the connection member 42 andram adaptor 16. The member 42 has a plurality of equidistantlycircumferentially spaced slots 39, for selectively receiving therein apin 49 carried by the adaptor 13, for locking the adaptor 13 in adesired position of angular orientation about its vertical axis.

The stripper-holddown assembly 46 includes a spacer member 47 and alower dishlike member 48 carried thereby. The spacer member 47 has anupper flange 50 which is connected to the plate 23 by suitablescrew-type fasteners 51 (iilustrated in dotted lines in FIG. 1).

A lower flange S2 is disposed beneath the upper flange 50 of the spacermember 47, being rigidly spaced therefrom and connected thereto by meansof a pair of vertically disposed spacer bars 53 and 54 to enable thedishlike plate member 48 to vertically span the tool and tool adaptor asshown in FIG. 1.

The lower flange portion 52 of the spacer member 47 is of generallyannular configuration, and has a lower and inner cutout portion 55,which receives the dishlike member 48, in upwardly abutting engagementtherein. The dishlike plate member 48 may be maintained in lateralposition by spring plunges 56, in resilient engagement against V-shapeddetent grooves or the like, 57 in the outer periphery of the dishlikemember 48. The member 48 is retained in vertical position by screws 58,which are threadably engaged within the spacer flange 52, the heads ofwhich are each in engagement with a retainer 60. Each retainer 60 islongitudinally slotted at 61 for movement toward and away from thelongitudinal central axis (not shown) of a punching tool 12, eachretainer 60 also being provided with an upwardly disposed stop 61, forlimiting the inward movement thereof.

The dishlike member 48 includes a depending boss 62, which is internallythreaded at 63, and in which is engaged a stripping cap 64. Thestripping cap 64 has a central portion 65, of predetermined thickness,terminating in a lower planar surface 66 which is substantially flushwith the lower planar surface portion 67 of the boss 62 of the dishlikemember 48. The central portion 55 of the stripping cap 64 generallyprovides the stripping edges, with the surface 67 of the boss 62generally transmitting holddown pressure to a workpiece (not shown)disposed between the surface 67 of the boss 62 and an upper surface 68of the die 15.

The die 15 is provided with suitable undercutting edges 70, whichsubstantially conform to the outlining configuration of punching tool12.

It is thus readily seen, that the spacer member 47 and dishlike member48 of the combination stripper-holddown assembly 46 are carriedcompletely free of and spaced from the tool 12 and its adaptor l3, andthat ready access is provided to the screw 45, between the flanges 50and 52 of the spacer 47, for retracting the screw 45 and permittingdownward movement of the tool adaptor 13, for removal of the same. Inorder to facilitate such removal of the tool 12 and too] adaptor 13, thestripping cap 64 may be threadably disengaged from the threads 63 of theboss 62, and the ram 14 moved upwardly away from the upper surface 68 ofthe die 15, in order to completely remove, and/or replace the tool 12and adaptor 13 with another tool and adaptor, as for example, inchanging tool size or shape, and for adaptability in receiving toolingof various manufacturers and the like,

The ready removal of the dishlike member 48 from the lower flange 52 ofthe spacer 47 provides a primary feature, for easy removal of the tool12 and adaptor 13, if such is desirable, by retracting the retainers 60to their outermost positions relative to the vertical axis of the tool12, followed by downward movement of the dishlike member 48 of theeutout 55.

With reference to FIG. 3, there is illustrated the manner in which thepunching tool 12 is moved vertically downwardly, during an initialpunching operation, with the stripper-hold down assembly 46 inengagement against an upper surface 68 of the lower die 15, and with thelower surfaces 66 and 67 of the plug 64 and boss 62 in substantiallyflush engagement against the upper surface 68 of the die 15. The tool 12is brought into engagement against the central portion 65 of the plug64, and shears the central portion 65 therefrom, to have an outliningconfiguration substantially equilivant t0 the configuration of the punch12 and die cutting edges 70. The punch 12 is then retracted, and thestripper is then ready to perform a stripping function.

Referring now to FIG 4, there is illustrated one stage of the punchingoperation, with a workpiece W disposed on the upper surface 68 of thedie 15, and clamped thereagainst by the force of the spring 25 exertedthrough the stripper-holddown assembly 46, with the newly cut outlininglip 71 of the plug 64 being adapted to strip punched material M awayfrom the tool 12, during an upward retraction of the tool 12, aftercompletion ofa punching operation on the workpiece W.

With particular reference to FIG. 5, there is illustrated an alternativeembodiment of a stripper cap 72, illustrated in a threaded engagementwithin a boss 73 (illustrated in phantom) of a dishlike member,generally similar to that 48 illustrated in FIG. 1. The stripper cap 72includes a carrier portion 74, having a clearance bore 75 therein and anouter threaded portion 76, terminating in a lower workpiece engagingsurface 77. An insert 78, of the desired thickness is disposed inwardlyof the retainer portion 74 of the cap 72, being inserted therein frombeneath, and retained in place by any suitable means, such as thesnap-ring fastener 80. The insert 78 is thus retained to be rotatablymovable within the major portion 74 of the cap 72, such that, if thetool and tool holder to be used therewith is angularly rotated about itsvertical axis (not shown) while the tool 12 is still disposed within theinsert 78, the insert 78 will also be rotated to the new position of thetool, in order to provide stripping for the tool in the newly selectedangular position thereof. It will be understood that the annular groove44 in the tool adaptor 13 facilitates the positioning of the tool 12 toa various number of positions about its vertical axis.

With reference to FIG. 6, there is illustrated a portion of a turrettype punch press machine, generally designated by the numeral 85, havinga stripper-holddown unit 86 carried thereby. A punching tool 87, and itsadaptor 88 are illustrated,

in removed and unsupporting relation with respect to thestripper-holddown unit 86.

The machine 85 includes a ram 90, movable vertically downwardly toward alower die 91, both the ram 90 and lower die 91 being fixed, except forrelative vertical movement. A ram adaptor 92 is provided, carried by theram 90, generally similar to the ram adaptor 16 of FIG. 1, and amounting plate 93 is slidably carried about a tubular surface portion 94of the ram adaptor, being resiliently urged downwardly by suitablecompression springs 95. A plurality of screws 96 provide motion limitingmeans, to limit the downward movement of the mounting plate 93, relativeto the upper portion of the ram adaptor 92.

At the lowermost end of the ram adaptor 92, there is provided anarcuately slotted groove 97, which is undercut to receive therein a head98 of the tool adaptor 88.

The tool 87 is vertically slidable within a rotatable turret plate 100,the turret plate 100 being adapted for rotation about its central axis(not shown), in the direction of the arrow of FIG. 7. Thus, the head 98of the tool adaptor 88, in an uppermost position of the tool 87 withinits turret plate bore 101, is adapted for registration within theundercut arcuate groove 97, and when the tool 87 is disposed directlybeneath the vertical axis of the ram 90, the arcuate movement of theturret plate 100 will be discontinued, leaving the tool 87 and itsadaptor 88 in position for vertical actuation by the downwardly movingram 90 and ram adaptor 92.

The stripper-holddown unit 86, as illustrated, may be of the plate type,and is normally carried upwardly against the lower surface 102 of therotatable turret plate 100, being secured thereto by one or more screws103, for limited vertical movement, but being upwardly biased bycompression springs 104.

When it is desired to perform a punching operation, a workpiece WP isdisposed on the upper surface of the die 91, and the ram 90 is actuatedfor vertical downward movement. The mounting plate 93 also movesvertically downwardly, carrying a vertical member 105 and a horizontalmember 106; the mounting plate 93, vertical member 105, and horizontalmember 106, cooperating to form a yoke-shaped or C-shaped actuationmeans, for transmitting vertically downwardly moving forces to thestripper-holddown unit 86 but serving to span the tool and tool adaptoras shown in FIG. 6. Thus, upon actuation of the ram 90, the horizontalmember 106 will engage the stripper-holddown unit 86 and move the sameinto clamping engagement against the workpiece WP, under a forceprovided through the springs 95, upon continued downward movement of theram 90, and consequent downward movement of the punching tool 87, untilthe workpiece WP is punched as desired, as illustrated in FIG. 8. Theram 90 may then be retracted with the springs 95 acting through theyokeshaped composite member to retain the stripper-holddown 86 againstthe workpiece, until the tool 87 is completely retracted, and thestripping edges 108 of the stripper-holddown unit 86 have stripped thepunched material M from the punch 87.

Continued upward retraction of the ram 90 will permit the mounting plate93, the vertical member 105 of the yoke, and the horizontal member 106to move vertically upwardly, to release the clamping force from thestripper-holddown unit 86, and consequently from the workpiece WP.

The rotatable turret plate may then be rotated about its axis (notshown) in the direction indicated by the arrow in FIG. 7, with the head98 of the tool adaptor 88 passing through the undercut arcuately slottedgroove 97, to clear the same, whereby a next adjacent tool carried bythe turret 100 may be brought into position beneath the ram 90.

It will be observed that the bottom surface 102 of the turret plate 100may be undercut, as at 108, in order to receive the horizontal member106 therein, for engagement of the horizontal member 106 with thestripper-holddown 86. In the alternative, some means (not shown) may beprovided for selectively moving the horizontal member 106 away from andbeneath the turret plate 100, upon indexing of a tool 87, to position.

It will also be noted that the stripper-holddown 86 has been illustratedas comprising a single plate, but that the same may be threaded forreceiving a stripper cap. as for example that iilustrated in FIG. 1, or,as for example that illustrated in FIG. 5, wherein stripping edges ofthe stripper cap thus utilized would function in substantially the samemanner as the stripping edges 107 ofthe stripper-holddown unit 106.

Various modifications may be made in the details of construction,materials, and the sequence of operation of the punch presses of thisinvention, all within the spirit and scope of the invention, as definedin the appended claims.

It will also be apparent that this invention is not limited to theparticular types of punching operations and punch presses disclosed butis adapted for using in notching and nibbling operations, and the like,in addition to hole punching operations.

As a further alternative, the dishlike member 48 may be retained invertical position within the spacer member 47 by horizontally disposedspring-loaded plungers or the like, carried by the spacer member 47 andengaged within blind bores in sides of the dishlike member 48, themember 48 being retained against undesirable angular movement byvertically disposed dowels carried by the spacer member and engagedwithin mating holes of the dishlike member.

It will be understood that the Abstract of the Disclosure" providedherein is intended to be a nontechnical description of the invention, inorder to comply with the Rules of Practice of the Patent Office, and isin no way intended to limit the scope of the invention as defined in theclaims.

I claim:

1. A punch press apparatus comprising a punch machine, including'meansfor driving a tool, a punching tool, a tool adaptor, a combinationstripper-holddown unit, a spacer, and means for mounting said spacer onsaid machine free of attachment to and lateral support from either ofsaid tool adaptor and said tool, for facilitating removal andreplacement of variously sized tools without disconnection orreplacement of said spacer relative to said machine, said spacer beingvertically rigid between said unit and said mounting means, beingconfigured to vertically span the tool and tool adaptor in the retractedposition of the tool while maintaining the stripperholddown unit spacedfrom the mounting means, and being disposed for moving said holddownunit into engagement with a workpiece under a desired force applied fromsaid tool driving through said spacer in the punching position of thetool.

2. The apparatus of claim 1, wherein said tool driving means includes aram and ram adaptor for transmitting driving forces to said tool throughsaid tool adaptor, said spacer and said unit being resilientlyvertically driveable by said ram adaptor.

3. The apparatus of claim 2, wherein said apparatus is of the singlestation type. v

4. The apparatus of claim 3, wherein fastening means are carried by saidram adaptor for releasably disengaging said tool adaptor from said ramadaptor.

5. The apparatus of claim 4, wherein said unit is provided withlaterally opening access means for manually actuating said fasteningmeans.

6. The apparatus of claim 2, wherein said apparatus is of the turrettype.

7. The apparatus of claim 6, wherein said machine includes a rotatableturret plate, and said mounting means connects said unit to said turretplate for vertical movement relative thereto.

8. The apparatus of claim 7, wherein said turret plate houses aplurality said tools for vertical movement therein, said tool adaptorbeing secured to said tool and being laterally engageable with said ramadaptor for vertical driving actuation thereby.

9. The apparatus of claim 7, wherein said spacer is generallyyoke-shaped in vertical section for transmitting unit-driving forcesfrom above said turret plate to said unit located therebeneath.

10. The apparatus of claim 1, wherein said unit has a planar holddownsurface means for clampingly' engaging a workpiece surface in outliningrelation to a workpiece portion to be engaged by said tool.

11. The apparatus of claim 10, wherein a readily removable stripper capis provided, comprising a part of said unit, said cap having surfacemeans thereon substantially in conformity with the peripheralconfiguration of said tool, and in substantially the same horizontalplane as said holddown surface means.

12. The apparatus of claim 11, wherein said cap is of the self-punchingtype, for formation of its stripping periphery by an initial downwardstroke of said tool.

13. The apparatus of claim 11, wherein said cap has a rotatable innerportion for following angular rotation of said tool about its verticalaxis.

14. A punch press apparatus comprising a punch press machine includingmeans for driving a tool, a punching tool, a tool adaptor, a combinationstripper-holddown unit, a spacer, and means for mounting said spacer onsaid machine free of attachment to and lateral support from either ofsaid tool adaptor and said tool, for facilitating removal andreplacement of variously sized tools without disconnection orreplacement of said spacer relative to said machine, wherein said tooldriving means includes a ram and ram adaptor for transmitting drivingforces to said tool through said tool adaptor, and said spacer and saidunit being resiliently vertically driveable by said ram adaptor, whereinsaid apparatus is of the single station type, wherein said mountingmeans comprises a plate member disposed about and carried by said ramadaptor and vertically movable relative thereto, said unit comprising adishlike member removably connected to said spacer.

15. The apparatus of claim 14, wherein said spacer carries horizontallymovable plunger means for engagement in recesses at sides of saiddishlike member and for fixing the lateral position of said dishlikemember within said spacer.

16. The apparatus of claim 14, wherein said spacer carries horizontallyslidable clamping means for clamping said dishlike member within saidspacer in a fixed vertical position relative to said spacer.

17. The apparatus of claim 14, wherein said spacer carries quick releasehorizontally movable plunger means for retaining said dishlike memberwithin said spacer.

18. A punch press apparatus comprising a punch press machine includingmeans for driving a tool, a punching tool, a tool adaptor, a combinationstripper-holddown unit, a spacer, and means for mounting said spacer onsaid machine free of attachment to and lateral support from either ofsaid tool adaptor and said tool, for facilitating removal andreplacement of variously sized tools without disconnection orreplacement of said spacer relative to said machine, wherein said tooldriving means includes a ram and ram adaptor for transmitting drivingforces to said tool through said tool adaptor, and said spacer and saidunit being resiliently vertically driveable by said ram adaptor, whereinsaid apparatus is of the single station type, wherein fastening meansare carried by said ram adaptor for releasably disengaging said tooladaptor from said ram adaptor, including an annular groove means in saidtool adaptor for selective positioning of said tool in a plurality ofannular positions about a vertical tool axis, said fastening means beingengageable within said annular groove means of said tool adaptor.

